\(5\frac{3}{4}:3+2\frac{1}{4}\times\frac{1}{3}-\frac{3}{8}\)
\(=\frac{23}{4}\times\frac{1}{3}+\frac{9}{4}\times\frac{1}{3}-\frac{3}{8}\)
\(=\left(\frac{23}{4}+\frac{9}{4}\right)\times\frac{1}{3}-\frac{3}{8}\)
\(=8\times\frac{1}{3}-\frac{3}{8}\)
\(=\frac{8}{3}-\frac{3}{8}\)
\(=\frac{55}{24}\)